Viscous compositions for use as ointments, salves, cosmetic creams and medicament carriers having petrolatum, lanolin, beeswax and the like as their base are known. Difficulties have been exhibited with such compositions in that the medicaments or other ingredients thereof tend to separate and segregate with time. In addition, their viscosity tends to change with temperature and with time, and the contained medicaments are not always readily released for absorption by the skin or other surface upon which they are used.
Mima (U.S. Pat. No. 3,881,012) teaches a pharmaceutical composition in which a liquid polyoxyethylene higher alcohol ether is mixed with an oily or fatty suppository base at elevated temperature and then cooled without stirring.
Frohmader (U.S. Pat. Nos. 2,627,938 and 2,628,187) discloses the addition of polyethylene to an oil base while stirring and heating the mixture until the polymer dissolves. The solution is then rapidly cooled without stirring through a temperature range which includes the cloud point.
An aluminum stearate gel of mineral oil is shown in Woodward (U.S. Pat. No. 2,792,329) and an oil and water emulsion of mineral oil using glycol monostearate as the emulsifier which is allowed to cool while mixing is shown in Wenmaekers (U.S. Pat. No. 4,124,720). Macek (U.S. Pat. No. 2,493,202) teaches the rapid cooling of a mixture of beeswax and peanut oil while stirring.
A new anhydrous pseudoplastic and thixotropic oleaginous vehicle has now been found which possesses hydrophobic characteristics intermediate between petroleum oil and conventional absorption bases, whose hydrophobic character can be controlled, and which can be used for the transport of water-active and/or water-sensitive ingredients.
Accordingly, it is the object of the present invention to provide a new anhydrous oleaginous vehicle whose viscosity can be reasonably controlled over a range that varies from a viscosity slightly higher than that of the unmodified base itself to that of a plastic or paste-like semi-solid; which is hydrophobic in character but miscible with water; which is non-toxic and non-irritating and as such is useful both internally as a vehicle for carrying medicaments and externally as a salve, ointment or cosmetic cream and the like. It is a further object of the invention to provide a method by which such a vehicle can be prepared. This and other objects of the invention will become apparent to those skilled in the art from the following detailed description.